Previous microwave antenna reflector assemblies have been high in cost because of the complexity of their structural design. The weight of these complex designs is large and assembly, shipment and installation is difficult and expensive. Close tolerances of parts are necessary for good accuracy and efficiency of the reflecting surface, adding to the cost. Snow and ice can accumulate on the reflector dish to degrade efficiency. Expensive servomechanisms for beam pointing are required due to the structural design and large weight supported by a pedestal mount.
The present invention largely eliminates all of the foregoing enumerated disadvantages of the previous microwave antenna art by use of a novel stressed skin inflatable construction. A hemisphere is formed by a thin metallic interior layer laminated to a formed plastic sheet and acts as the antenna reflector while a similar microwave transparent hemispherical cover is formed which enables pressurization of the interior while acting as a protective cover for the reflector, thus preventing accumulation of snow and ice on the reflector dish. A central rigid cylindrical support member for the stressed skin reflector and cover carries a microwave transparent plastic hollow trunnion tube at its central diameter inside which the antenna feed is placed. Bearings in a simple pipe support frame permit rotation of the reflector assembly on the trunnions and adjustment of antenna beam elevation. The antenna feed position can be moved along the focal plane of the reflector inside the hollow trunnion tube to permit limited adjustment of antenna beam azimuth angle with a spherical reflector, while with a parabolic reflector, the antenna feed position is at the axial focal point of the reflector inside the trunnion tube and the antenna support frame is steered for adjustment of antenna beam azimuth angle. Weight of the invention is radically reduced by the novel stressed skin construction to a fraction of the weight of previous antennas, and the reflector and cover assembly can be deflated for easy shipment. Installation is comparatively simple and easy. For point to point or geo-stationary satellite communication antenna beam pointing is sufficiently convenient. The pipe support frame is simple, with locally obtainable material. Cost and weight are radically reduced below that of the previous art while reflector efficiency is raised by the improved accuracy of the novel stressed skin construction of the reflector of present invention.